1. Technical Field
The present invention relates to a fixation device for an electronic display, especially to a device which can easily, stably and firmly fix an electronic display on a printed circuit board of electronic apparatuses.
2. Prior Art
An electronic display such as a liquid-crystal or flourescent display tube for digitally or graphically showing a volume of sound, frequency, revolution speed, time measurement result or the like is attached to home electric appliances such as television set, radio, video tape recorder, microwave oven, stereo, and measuring instrument. Although various kinds of fixation means have been proposed, they have some problems, i.e., lack of positioning stability and requirement of much time to furnish the device due to the complicated process. As a result, the efficiency in respect to the productivity of electric appliances is decreased. A two-side sticking tape or an adhesive agent is stuck to the printed circuit board , a buffer made of chloroprene sponge is stuck to the tape or the adhesive agent, another two-side-sticking tape or adhesive agent is stuck to the buffer, the back of the electronic display is stuck to the latter two-side-sticking tape or adhesive agent, and the terminals of the electronic display are inserted into the insertion holes of the printed circuit board so as to support the electronic display.
However, such a device includes the following problems. Firstly, it is troublesome to apply an adhesive agent or remove the covering paper from a two-side-sticking tape. Especially, when the adhesive agent is used, it is apt to be influenced by the temperature while at work. Secondly, it is also difficult to attach the electronic display to the circuit board in an accurate position. When the attached display gets out of its position, the terminals must be forced to be bent. It sometimes makes impossible to insert the terminals into the insertion holes of the printed circuit board. Furthermore, some other problems are found, e.g., demounting and reattachment of the display is difficult, and the spacing height is not determined.
The object of the present invention is to provide a fixation device for an electronic display by which an electronic display can be easily and surely fixed on a printed circuit board. The present invention has a constitution for solving the abovementioned problems. The constitution is such that the fixation device includes a platelike (i.e., plate-like) rest on which the electronic display is put, holding members formed at each of opposed longitudinal edges of the rest to hold the electronic display, fixing members formed on the back surface of the platelike rest to fix the rest on the circuit board, attachment members composed of a pair of projections and insertion holes which are respectively formed on the surface of the platelike rest and on at least one of the abovementioned holding members, and engaging members for engaging the holding members at the position where the electronic display is retained by the holding members.
The platelike rest has a form corresponding to that of the electronic display, and is fixed on the printed circuit board by the fixing members such as snaps with engaging projections, the tip of each of which is shaped as an arrowhead.
The holding members are formed at each of opposed longitudinal edges of the rest so as to hold the electronic display and fix it on the platelike rest. However, at least one of the holding members is formed separately from the rest and attached to the rest by a pair of attachment members composed of projections and insertion holes. Each one of the attachment members is respectively formed on the platelike rest and the holding members, and it can pivot around the projection.
On the other hand, engaging members are formed on the platelike rest so as to fix the pivotaly movable holding members at the position where the electronic display is retained by the holding members. Therefore, the holding members are immovable even by a vibration or the like after the electronic display is retained. All the members and elements described above may be made of various kinds of plastics such as a polyamide condensation polymer or a polyester condensation polymer.
In respect to the electronic display fixation device with the abovementioned constitution according to the present invention, the display can be firmly retained by the holding members, and the platelike rest is stably fixed on the circuit board by the fixing member, thereby the positioning accuracy of the display can be improved. Furthermore, attachment and demounting of the display become much easier by handling the holding members which can pivot via the attachment members.